Unexpected consequences of a rebelion

So, I had a nobility rebelion in around year 1380. They did not put up a decent fight, whole thing took about a year. 'Huh, what an easy estate happines reset' I thought.

Fast forward to year 1688, welcome to the second nobility rebelion. About 1/6 of my provinces turn blue, all of them nowhere near my capital.

First thing I see after rebelion popup is my that my ruler bit the dust and I am in regency now. Regency lasted whole 3 days before his 9 year old son followed in his stead. New queen is 18 y.o. older sister of late prince.

Fight against rebellion goes smoothly, as expected nobels couldn't rase a decent army. Whole thing is a boring slog of clicking through all of my army stacks and all off the rebelling provinces (biggest casualty of war - full stack of regulars marched directly into not so frozen lake).

Now, rebelion is all but crushed, just couple of provinces left to take. Another popup show up - I'm in regency, agian. Now this, third, I mind you, time, I actually bothered to look up what happened to poor girl. She was executed, by my vassal's ruler, who is loyal, and not participating in a war at all. Like, wtf.

Now I'm stuck with 3 y.o. ruler and regency, fml.